A2919

• 750 mA Continuous Output Current
• 45 V Output Sustaining Voltage
• Internal Clamp Diodes
• Internal PWM Current Control
• Low Output Saturation Voltage
• Internal Thermal Shutdown Circuitry
• Half- or Quarter-Step Operation of Bipolar Stepper Motors

Description

The A2919SB and A2919SLB motor drivers are designed to drive both windings of a bipolar stepper motor or bidirectionally control two dc motors. Both bridges are capable of sustaining 45 V and include internal pulse-width modulation (PWM) control of the output current to 750 mA. The outputs have been optimized for a low output-saturation voltage drop (less than 1.8 V total source plus sink at 500 mA).

For PWM current control, the maximum output current of A2919 is determined by the user's selection of a reference voltage and sensing resistor. Two logic-level inputs select output current limits of 0%, 41%, 67%, or 100% of the maximum level. A PHASE input to each bridge determines load current direction.

The bridges include both ground clamp and flyback diodes for protection against inductive transients. Internally generated delays prevent cross-over currents when switching current direction. Special power-up sequencing is not required. Thermal protection circuitry disables the outputs if the chip temperature exceeds safe operating limits.